package com.fwj.core.common.config;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

/**
 * @Author: fwj
 * @Data: 2022/1/2 22:34
 * @Version 1.0
 * @Description: 获取Spring应用上下文注入对象
 */

@Component
public class SpringContextHolder implements ApplicationContextAware {

    private static ApplicationContext applicationContext;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        SpringContextHolder.applicationContext = applicationContext;
    }

    public static ApplicationContext getApplicationContext(){
        assertApplicationContext();
        return applicationContext;
    }

    /**
     * 根据名字获取注入对象
     * */
    public static <T> T getBean(String beanName){
        assertApplicationContext();
        return (T)applicationContext.getBean(beanName);
    }

    /**
     * 根据类型获取注入对象
     * */
    public static <T> T getBean(Class<T> requiredType){
        assertApplicationContext();
        return applicationContext.getBean(requiredType);
    }

    private static void assertApplicationContext() {
        if (SpringContextHolder.applicationContext == null){
            throw new RuntimeException("应用上下文为空，未注入SpringContextHolder!!!");
        }
    }
}
